Bowling pin



Jan 23, 1962 F. E. sATcHELL ETAL 3,018,105

BOWLING PIN Filed May 6, 1959 3,018,106 BWLING PIN Fred E. Satcheii and Louis J. Trier, Muskegon, Mich., as-

signors to Brunswick Corporation, a corporation of Delaware Filed May 6, 1959, Ser. No. 811,465 11 Claims. (Cl. 273-82) nThis invention relates to an impact withstanding article and more particularly to a bowling pin having a cover including a non-stress transmitting area.

It is the principal object of this invention to provide an impact withstanding article of the character described.

It is another object of this invention to provide an impact withstanding article including a wooden body having a resilient cover adhered thereto, with the cover including a non-stress transmitting area arranged to prevent slabbing of the wooden body.

It is a further object of this invention to provide a bowling pin including a wooden body having neck and belly portions, the pin being covered by a first thin layer of resilient cover material adhered to the body, and having a thin layer of parting film applied to said first layer about the belly portion of the pin and a second thin layer of cover material adhered to the firs-t layer with the parting film therebetween thereby providing a nonstress transmitting area of non-adherence between said films over the belly portion to prevent slabbing of the wooden body.

It is yet another object of this invention to provide a method for coating an impact withstanding article including the steps of adhering a first layer of resilient cover material to the article, applying a thin parting film over a portion of said first layer, and adhering a second layer of cover material to said first layer with said film therebetween, to provide a non-stress transmitting area of non-adherence between said layers.

Other objects and advantages of this invention will be apparent from the following description taken in connection with the accompanying drawings.

Of the drawings:

FIGURE 1 is a front elevational view of the bowling FIGURE 2 is an enlarged partial vertical sectional view taken along the line 2-2 of FIGURE l and showing a portion of the cover greatly enlarged; and

FIGURE 3 is an enlarged horizontal sectional view taken along the line 3-3 of FIGURE l.

Bowling pins such as that shown in FiGURE 1 are commonly made of wood. Several types of wood may be used, for example, maple, beech, or pecan, but maple wood is preferred. The pin 1i) includes a neck 11, a belly 12 and a base portion 13. For protection and preservation, the entire pin is covered with a protective resilient cover 14 which is bonded or adhered to the wooden pin at 15.

The use of the resilient cover 14 though necessary, has presented a rather serious problem to the manufacturers of impact withstanding articles such as bowling pins, since the cover under impact from bowling balls and the like tends to grow or enlarge in size. This growing generally occurs in the impact area adjacent the belly 12 of the pin and results in a stress through the adhesive bond 15 to the wood beneath. The stress applied to the wood is apparently spread evenly around the entire periphery of the pin 14). However, since the pin is weakest in a direction perpendicular to the grain of the wood as shown by the arrows in FIGURE 3, the stress results in flat grain failure or splintering of the wood in the areas 18a which is often called slabbing by the industry.

This slabbing or fiat grain failure may be avoided in accordance with the teaching of this invention by pro- Patented Jan. 23, 1962 viding a non-stress transmitting area 16 in the cover. This non-stress transmitting area is preferably located at the impact point on the belly 12 of the pin and extends around the periphery of the pin. Preferably, the nonstress transmitting area is about three inches wide.

Referring now to FIGURE 2, which more clearly shows the non-stress transmitting area, it can be seen that it includes a first layer 17 of a resilient cover material which is bonded at 15 by an adhesive to the surface of the Wooden pin. A second layer 18 of cover material overlies the first layer 17 but is unconnected thereto and separated therefrom by a space 19. The layers 17 and 18 merge into a single layer at place 20 adjacent to the area 16. As a bowling ball impacts against the nonstress transmitting area 16 of the pin, the second layer 18 may grow as in the past but since it is unconnected to the first layer, there is no stress transmitted through the first layer 17 and the adhesive 15 to the pin beneath, thereby substantially preventing slabbing.

The resilient cover material 14 is generally applied to the pin 10 by dip coating. Thereafter, it is cured. Several coats of material are normally applied in order to provide the desired thickness and resiliency. However, the result is very like a single layer of material.

One method of introducing the non-stress transmitting area into the cover material includes the use of a parting film (not shown) which is applied over one of the early coats of cover material. Thereafter, the remainder of the cover material is coated on the pin. Since the remainder or second layer 18 of cover material is prevented from adhering to the first layer 17 by the parting film, the separation or space 19 occurs, thus providing the non-stress transmitting area 16. The width of the parting film determines the width of the non-stress transmitting area, or in other words, the width of the space 19.

Naturally there are numerous materials which may be satisfactorily used to provide the parting film. The only limitations on these materials are that they cannot adversely affect the cover material throughout the useful life of the pin and that they must prevent the second layer 18 from adhering -to the first layer 17. As examples of such materials, a water solution of polyvinyl alcohol and a solution of cellulose acetate butyrate dissolved in a 50-50 solution of ethyl acetate and toluene may be mentioned. Of these two, the cellulose acetate butyrate is preferred.

A cover material 14 useful on impact withstanding articles such as bowling pins is a resilient plastic material which can be applied in a solution form and cured in situ with relative ease. There are numerous materials which are satisfactory for this purpose, among which are nitrocellulose and ethyl cellulose, which can easily be applied in solution form andndried.

In the construction of a bowling pin according to this invention, a maple pin is first immersed in a liquid polyvinyl acetate adhesive which will bond the cover material to the surface of the wood. Thereafter, the pin is air dried at room temperature for about 15 minutes before it is immersed in a solution of nitrocellulose lacquer. This solution contains 7l parts of nitrocellulose having a viscosity of 25 to 30 cps., 22 parts dibutyl phthalate and 7 parts of a plasticizer which is a castor oil modified sebacie acid ester with a diglycol. This nitrocellulose mixture is dissolved in a mixed solvent containing 50 parts ethyl acetate, l5 parts ethanol and 35 parts toluene to make up a solution containing 25% solids. After the pin is thoroughly coated with this nitrocellulose lacquer it is withdrawn fro-m the coating bath and allowed to dry at room temperature for about 2O minutes. Thereafter, it is reimmersed in the nitrocellulose lacquer and then allowed to dry at room temperature for about 16 hours.

amato@ Subsequently, the pin is coated with two slightly different ethyl cellulose solutions. The first being of medium ethoxy active ethyl cellulose having a viscosity of about 50 cps. dissolved in a mixed solvent of 80 parts toluene and parts butyl acetate to make u p a 20% solution of the ethyl cellulose. The second ethyl cellulose solution contains a medium ethoxy ethyl cellulose jell lacquer having a viscosity of about 100 cps. which vis dissolved in toluene to make a 20% solution of ethyl cellulose. After immersion in each of these two ethyl cellulose solutions, the pin is dried for about one hour ,at 160 F.

After the second ethyl cellulose coat has dried, the parting film is applied. kIt is painted on the surface of theethyl cellulose film to a thickness of about 2 mils. A 10% solution of cellulose acetate butyrate in a mixed solvent of 50% ethyl acetate and 50% toluene is used. 'The parting lm is then dried overnight at room temperature. Thereafter, three additional coats of the medium ethoxy ethyl cellulose jell lacquer in toluene are added. Each coat is dried overnight at room temperature before the addition of the next coat. Lastly, an overcast to provide dirt resistance is added. For this purpose, the solution of nitrocellulose lacquer described above may be used. The overcast is also about 2 mils thick.

The results of these steps of manufacture give a first layer 17 of resilient cover material which is from about 10420 mils in thickness. The second layer 18 of cover material is about 40-50 mils in thickness and as already stated, the parting vfilms and the overcast are about 2 mils thick. All-parts and percentages in the above example are by weight.

Having described out invention as related to the embodiment set out herein, it is our intention that the invention be not limited by any of the details of de- ,:scription, unless otherwise specified, but rather be con- ,strued broadly within its spirit and scope as set out in the accompanying claims.

We claim: 1. An impact withstanding article of the character described, comprising: a wooden body having a thin resilient cover adhered thereto, said cover including within itself and under the surface thereof a non-stress transmitting area located at about the normal impact receiving portion of said article and arranged to prevent slabbing of said wooden body comprising unconnected layiers of cover material.

2. The article of claim 1 wherein said area extends about the periphery of said article at about said normal impact receiving portion.

3. The article of claim 2 wherein said layers merge into a single-layer at a place adjacent to said area.

4. An impact withstanding article of the character described, comprising: a wooden body having a thin resilient cover adhered thereto, said cover including within itself and under the surface thereof a non-stress transmitting area located about the periphery of said article at Aabout its normal iinpact receiving portion to prevent slabbing of said wooden body comprising a first layer of said cover adhered to said body, a parting iilm over said first layer and a second layer of said cover positioned over said parting lm, thereby providing a non-stress transmitting area of non-adherence between said layers to prevent slabbing of said wooden body,

5. A bowling pin, comprising: a wooden body having neck and belly portions and a cover comprising a first thin layer of resilient cover material adhered to said body and a second thin layer of said cover material adhered to said first layer but having a portion unconnected thereto thereby providing a non-stress `transmitting area of nonadherence between said layers over said belly pontion to prevent slabbing of the wooden body.

6. A bowling pin, comprising: a wooden body having neck and belly portions and al cover comprising a lirst thin layer of resilient cover material adhered to said body; a thin layer of parting lm applied `to said iirst layer about the belly portion of said pin; and a second thin layer of said cover material adhered to said first layer with said parting film therebetween, thereby providing a non-stress transmitting area of non-adherence between said layers over said belly portion to prevent slabbing of the wooden body.

7. The bowling pin of claim 6 wherein said iirst layer is from about 10-20 mils in thickness, said lm is about 2 mils thick, and said second layer is about 40-50 mils thick.

8. In amethod of coating a wooden impact withstanding article of the character described, to provide a resilient non-stress transmitting cover for preventing slabbing of the wooden article, the steps of: adhering a first layer of resilient cover material over the entire surface of said article, applying a thin parting film over a portion of said first layer and adhering a second layer of cover material to said first layer with said iilm therebetween to provide a non-stress transmitting area of non-adherence between said layers.

9. In the method of claim 8 the steps of curing each of said layers after application to said article.

10. In the method of claim 8 wherein said film is applied at about the normal impact area of said article.

11. In the method offclaim 8 wherein said article is a bowling pin and said film is applied about the periphery of the belly of said pin in the normal impact area.

References Cited in the tile of this patent UNITED STATES PATENTS 649,745 Niemeyer May 15, 1900 1,946,208 Hampton Feb. 6, 1934 2,276,685 Bright Mar. 17, 1942 2,876,011 Hunt Mar. 3, 1959 

